Two young boys are accused in court documents of planning to kill one of their female classmates at their elementary school in Washington state.

The boys, ages 10 and 11, devised a plan to lure their female classmate away from Fort Colville Elementary School in Washington in order to kill her, school officials said, according to court documents released this week.

The 11-year-old told school officials that he and his accomplice had been planning their attack, initially citing what they considered the girl's annoying personality to school officials as their motive to kill, according to the documents.

Their plan unraveled Feb. 7, however, after a fourth-grader witnessed the 11-year-old removing a knife from his backpack on the school bus the morning of their planned attack, according to the documents. The student informed a teacher of the sighting upon arriving to school, which is when the two boys' backpacks were searched.

A knife, a .45 semi-automatic pistol and a full ammunition clip were discovered in the 10-year-old's backpack, the court papers said.

The 11-year-old allegedly explained the plan to school officials.

"I was going to kill her with the knife and [the 10-year-old] was supposed to use the gun to keep anyone from trying to stop me or mess up our plan," the 11-year-old said, according to court records.

The two boys allegedly told a third student of their plot, offering to pay him $80 if he remained silent on the proposed plan, prosecutors said.

The boys both told officers, according to the court documents, that although they had been friends with their main, female target for several months, she became rude and began to pick on them, which triggered their rage.

The 10-year-old boy said he obtained the firearm from the room of his older brother, who had taken the weapon from their dead grandfather's home a few months prior, prosecutors said. Officers confirmed the weapon was registered to the grandfather's name.

The two boys were taken to Coleville's juvenile detention facility, Martin Hall, where they were being held on a $100,000 bond, according to court records and Stevens County Prosecutor Tim Rasmussen.

They are charged with conspiracy to commit first-degree murder, tampering with a witness and conspiracy to possess a firearm, according to The Spokesman-Review.

Attorneys for the two boys declined to comment on the accusations.

Rasmussen told ABC News that in the state of Washington, there is a presumption that children between the ages of 8 to 12 do not have the mental capacity to understand crimes they are planning to commit. After the age of 12, a child is deemed to have that mental capacity.

A mental capacity hearing has been scheduled for the two boys on Feb. 20. At that meeting, evidence will be presented to determine whether or not the mental capacity presumption can be overturned. Several factors, such as the age and maturity of the suspects, if they knew the acts involved were inherently wrong, and whether there was an attempt for secrecy, are just a few factors to be considered, said Rasmussen.

If convicted, however, the boys could be incarcerated in a juvenile hall, possibly up to the age of 18.